/* ----------------------------------------------------------------------
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
*
* $Date:        19. March 2015
* $Revision: 	V.1.4.5
*
* Project:      CMSIS DSP Library
* Title:	    arm_cmplx_mat_mult_q15.c
*
* Description:	 Q15 complex matrix multiplication.
*
* Target Processor:          Cortex-M4/Cortex-M3/Cortex-M0
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*   - Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*   - Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in
*     the documentation and/or other materials provided with the
*     distribution.
*   - Neither the name of ARM LIMITED nor the names of its contributors
*     may be used to endorse or promote products derived from this
*     software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* POSSIBILITY OF SUCH DAMAGE.
* -------------------------------------------------------------------- */
#include "arm_math.h"

/**
 * @ingroup groupMatrix
 */

/**
 * @addtogroup CmplxMatrixMult
 * @{
 */


/**
 * @brief Q15 Complex matrix multiplication
 * @param[in]       *pSrcA points to the first input complex matrix structure
 * @param[in]       *pSrcB points to the second input complex matrix structure
 * @param[out]      *pDst points to output complex matrix structure
 * @param[in]		*pScratch points to the array for storing intermediate results
 * @return     		The function returns either
 * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
 *
 * \par Conditions for optimum performance
 *  Input, output and state buffers should be aligned by 32-bit
 *
 * \par Restrictions
 *  If the silicon does not support unaligned memory access enable the macro UNALIGNED_SUPPORT_DISABLE
 *	In this case input, output, scratch buffers should be aligned by 32-bit
 *
 * @details
 * <b>Scaling and Overflow Behavior:</b>
 *
 * \par
 * The function is implemented using a 64-bit internal accumulator. The inputs to the
 * multiplications are in 1.15 format and multiplications yield a 2.30 result.
 * The 2.30 intermediate
 * results are accumulated in a 64-bit accumulator in 34.30 format. This approach
 * provides 33 guard bits and there is no risk of overflow. The 34.30 result is then
 * truncated to 34.15 format by discarding the low 15 bits and then saturated to
 * 1.15 format.
 *
 * \par
 * Refer to <code>arm_mat_mult_fast_q15()</code> for a faster but less precise version of this function.
 *
 */




arm_status arm_mat_cmplx_mult_q15(
    const arm_matrix_instance_q15 *pSrcA,
    const arm_matrix_instance_q15 *pSrcB,
    arm_matrix_instance_q15 *pDst,
    q15_t *pScratch)
{
    /* accumulator */
    q15_t *pSrcBT = pScratch;                      /* input data matrix pointer for transpose */
    q15_t *pInA = pSrcA->pData;                    /* input data matrix pointer A of Q15 type */
    q15_t *pInB = pSrcB->pData;                    /* input data matrix pointer B of Q15 type */
    q15_t *px;                                     /* Temporary output data matrix pointer */
    uint16_t numRowsA = pSrcA->numRows;            /* number of rows of input matrix A    */
    uint16_t numColsB = pSrcB->numCols;            /* number of columns of input matrix B */
    uint16_t numColsA = pSrcA->numCols;            /* number of columns of input matrix A */
    uint16_t numRowsB = pSrcB->numRows;            /* number of rows of input matrix A    */
    uint16_t col, i = 0u, row = numRowsB, colCnt;  /* loop counters */
    arm_status status;                             /* status of matrix multiplication */
    q63_t sumReal, sumImag;

#ifdef UNALIGNED_SUPPORT_DISABLE
    q15_t in;                                      /* Temporary variable to hold the input value */
    q15_t a, b, c, d;
#else
    q31_t in;                                      /* Temporary variable to hold the input value */
    q31_t prod1, prod2;
    q31_t pSourceA, pSourceB;
#endif

#ifdef ARM_MATH_MATRIX_CHECK
    /* Check for matrix mismatch condition */
    if((pSrcA->numCols != pSrcB->numRows) ||
            (pSrcA->numRows != pDst->numRows) || (pSrcB->numCols != pDst->numCols))
    {
        /* Set status as ARM_MATH_SIZE_MISMATCH */
        status = ARM_MATH_SIZE_MISMATCH;
    }
    else
#endif
    {
        /* Matrix transpose */
        do
        {
            /* Apply loop unrolling and exchange the columns with row elements */
            col = numColsB >> 2;

            /* The pointer px is set to starting address of the column being processed */
            px = pSrcBT + i;

            /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
             ** a second loop below computes the remaining 1 to 3 samples. */
            while(col > 0u)
            {
#ifdef UNALIGNED_SUPPORT_DISABLE
                /* Read two elements from the row */
                in = *pInB++;
                *px = in;
                in = *pInB++;
                px[1] = in;

                /* Update the pointer px to point to the next row of the transposed matrix */
                px += numRowsB * 2;

                /* Read two elements from the row */
                in = *pInB++;
                *px = in;
                in = *pInB++;
                px[1] = in;

                /* Update the pointer px to point to the next row of the transposed matrix */
                px += numRowsB * 2;

                /* Read two elements from the row */
                in = *pInB++;
                *px = in;
                in = *pInB++;
                px[1] = in;

                /* Update the pointer px to point to the next row of the transposed matrix */
                px += numRowsB * 2;

                /* Read two elements from the row */
                in = *pInB++;
                *px = in;
                in = *pInB++;
                px[1] = in;

                /* Update the pointer px to point to the next row of the transposed matrix */
                px += numRowsB * 2;

                /* Decrement the column loop counter */
                col--;
            }

            /* If the columns of pSrcB is not a multiple of 4, compute any remaining output samples here.
             ** No loop unrolling is used. */
            col = numColsB % 0x4u;

            while(col > 0u)
            {
                /* Read two elements from the row */
                in = *pInB++;
                *px = in;
                in = *pInB++;
                px[1] = in;
#else

                /* Read two elements from the row */
                in = *__SIMD32(pInB)++;

                *__SIMD32(px) = in;

                /* Update the pointer px to point to the next row of the transposed matrix */
                px += numRowsB * 2;


                /* Read two elements from the row */
                in = *__SIMD32(pInB)++;

                *__SIMD32(px) = in;

                /* Update the pointer px to point to the next row of the transposed matrix */
                px += numRowsB * 2;

                /* Read two elements from the row */
                in = *__SIMD32(pInB)++;

                *__SIMD32(px) = in;

                /* Update the pointer px to point to the next row of the transposed matrix */
                px += numRowsB * 2;

                /* Read two elements from the row */
                in = *__SIMD32(pInB)++;

                *__SIMD32(px) = in;

                /* Update the pointer px to point to the next row of the transposed matrix */
                px += numRowsB * 2;

                /* Decrement the column loop counter */
                col--;
            }

            /* If the columns of pSrcB is not a multiple of 4, compute any remaining output samples here.
             ** No loop unrolling is used. */
            col = numColsB % 0x4u;

            while(col > 0u)
            {
                /* Read two elements from the row */
                in = *__SIMD32(pInB)++;

                *__SIMD32(px) = in;
#endif

                /* Update the pointer px to point to the next row of the transposed matrix */
                px += numRowsB * 2;

                /* Decrement the column loop counter */
                col--;
            }

            i = i + 2u;

            /* Decrement the row loop counter */
            row--;

        }
        while(row > 0u);

        /* Reset the variables for the usage in the following multiplication process */
        row = numRowsA;
        i = 0u;
        px = pDst->pData;

        /* The following loop performs the dot-product of each row in pSrcA with each column in pSrcB */
        /* row loop */
        do
        {
            /* For every row wise process, the column loop counter is to be initiated */
            col = numColsB;

            /* For every row wise process, the pIn2 pointer is set
             ** to the starting address of the transposed pSrcB data */
            pInB = pSrcBT;

            /* column loop */
            do
            {
                /* Set the variable sum, that acts as accumulator, to zero */
                sumReal = 0;
                sumImag = 0;

                /* Apply loop unrolling and compute 2 MACs simultaneously. */
                colCnt = numColsA >> 1;

                /* Initiate the pointer pIn1 to point to the starting address of the column being processed */
                pInA = pSrcA->pData + i * 2;


                /* matrix multiplication */
                while(colCnt > 0u)
                {
                    /* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */

#ifdef UNALIGNED_SUPPORT_DISABLE

                    /* read real and imag values from pSrcA buffer */
                    a = *pInA;
                    b = *(pInA + 1u);
                    /* read real and imag values from pSrcB buffer */
                    c = *pInB;
                    d = *(pInB + 1u);

                    /* Multiply and Accumlates */
                    sumReal += (q31_t) a * c;
                    sumImag += (q31_t) a * d;
                    sumReal -= (q31_t) b * d;
                    sumImag += (q31_t) b * c;

                    /* read next real and imag values from pSrcA buffer */
                    a = *(pInA + 2u);
                    b = *(pInA + 3u);
                    /* read next real and imag values from pSrcB buffer */
                    c = *(pInB + 2u);
                    d = *(pInB + 3u);

                    /* update pointer */
                    pInA += 4u;

                    /* Multiply and Accumlates */
                    sumReal += (q31_t) a * c;
                    sumImag += (q31_t) a * d;
                    sumReal -= (q31_t) b * d;
                    sumImag += (q31_t) b * c;
                    /* update pointer */
                    pInB += 4u;
#else
                    /* read real and imag values from pSrcA and pSrcB buffer */
                    pSourceA = *__SIMD32(pInA)++;
                    pSourceB = *__SIMD32(pInB)++;

                    /* Multiply and Accumlates */
#ifdef ARM_MATH_BIG_ENDIAN
                    prod1 = -__SMUSD(pSourceA, pSourceB);
#else
                    prod1 = __SMUSD(pSourceA, pSourceB);
#endif
                    prod2 = __SMUADX(pSourceA, pSourceB);
                    sumReal += (q63_t) prod1;
                    sumImag += (q63_t) prod2;

                    /* read real and imag values from pSrcA and pSrcB buffer */
                    pSourceA = *__SIMD32(pInA)++;
                    pSourceB = *__SIMD32(pInB)++;

                    /* Multiply and Accumlates */
#ifdef ARM_MATH_BIG_ENDIAN
                    prod1 = -__SMUSD(pSourceA, pSourceB);
#else
                    prod1 = __SMUSD(pSourceA, pSourceB);
#endif
                    prod2 = __SMUADX(pSourceA, pSourceB);
                    sumReal += (q63_t) prod1;
                    sumImag += (q63_t) prod2;

#endif /*      #ifdef UNALIGNED_SUPPORT_DISABLE */

                    /* Decrement the loop counter */
                    colCnt--;
                }

                /* process odd column samples */
                if((numColsA & 0x1u) > 0u)
                {
                    /* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */

#ifdef UNALIGNED_SUPPORT_DISABLE

                    /* read real and imag values from pSrcA and pSrcB buffer */
                    a = *pInA++;
                    b = *pInA++;
                    c = *pInB++;
                    d = *pInB++;

                    /* Multiply and Accumlates */
                    sumReal += (q31_t) a * c;
                    sumImag += (q31_t) a * d;
                    sumReal -= (q31_t) b * d;
                    sumImag += (q31_t) b * c;

#else
                    /* read real and imag values from pSrcA and pSrcB buffer */
                    pSourceA = *__SIMD32(pInA)++;
                    pSourceB = *__SIMD32(pInB)++;

                    /* Multiply and Accumlates */
#ifdef ARM_MATH_BIG_ENDIAN
                    prod1 = -__SMUSD(pSourceA, pSourceB);
#else
                    prod1 = __SMUSD(pSourceA, pSourceB);
#endif
                    prod2 = __SMUADX(pSourceA, pSourceB);
                    sumReal += (q63_t) prod1;
                    sumImag += (q63_t) prod2;

#endif /*      #ifdef UNALIGNED_SUPPORT_DISABLE */

                }

                /* Saturate and store the result in the destination buffer */

                *px++ = (q15_t) (__SSAT(sumReal >> 15, 16));
                *px++ = (q15_t) (__SSAT(sumImag >> 15, 16));

                /* Decrement the column loop counter */
                col--;

            }
            while(col > 0u);

            i = i + numColsA;

            /* Decrement the row loop counter */
            row--;

        }
        while(row > 0u);

        /* set status as ARM_MATH_SUCCESS */
        status = ARM_MATH_SUCCESS;
    }

    /* Return to application */
    return (status);
}

/**
 * @} end of MatrixMult group
 */
